Currently, the growth of the global population leads to an increase in demand for agricultural products. Expanding the obtaining and consumption of food products results in a scale up in the amount of by-products formed, the development of processing methods for which is becoming an urgent task of modern science. Collagen and keratin make up a significant part of the animal origin protein waste, and the potential for their biotechnological application is almost inexhaustible. The specific fibrillar structure allows collagen and keratin to be in demand in bioengineering in various forms and formats, as a basis for obtaining hydrogels, nanoparticles and scaffolds for regenerative medicine and targeted drug delivery, films for the development of biodegradable packaging materials, etc. This review describes the variety of sustainable sources of collagen and keratin and the beneficial application multiformity of these proteins.

Every year, the size of the human population grows; with it, the need for agricultural products increases. This leads to an increment in the volume of waste, including hard-to-degrade keratin-rich ones, such as feathers. Currently, most of the agro-industrial complex protein by-products are utilized by incineration, landfilling, and chemical hydrolysis. Such methods do not meet modern trends in the development of a sustainable economy, negatively affecting the environment and humans, and preventing the reusing of waste. An alternative is biodegradation, which consists of the application of living organisms and their enzymes to recycle by-products. This approach is not only sustainable, but also makes it possible to obtain products of waste hydrolysis that are in demand for the manufacture of fertilizers and feed additives. This brings the development of agriculture closer to a circular economy and makes the recycling process more profitable. This review article emphasizes the significance of keratinolytic microorganisms and keratinases for the improvement of green methods for processing hard-to-degrade protein waste of the agro-industrial complex, which is necessary for sustainable economic development.

The high demand for keratinolytic enzymes and the modest presentation of fungal keratinase diversity studies in scientific sources cause a significant interest in identifying new fungal strains of keratinase producers, isolating new enzymes and studying their properties. Four out of the 32 cultures showed a promising target activity on protein-containing agar plates—Aspergillus amstelodami A6, A. clavatus VKPM F-1593, A. ochraceus 247, and Cladosporium sphaerospermum 1779. The highest values of keratinolytic activity were demonstrated by extracellular proteins synthesized by Aspergillus clavatus VKPM F-1593 cultivated under submerged conditions on a medium containing milled chicken feathers. The enzyme complex preparation was obtained by protein precipitation from the culture liquid with ammonium sulfate, subsequent dialysis, and lyophilization. The fraction of a pure enzyme with keratinolytic activity (pI 9.3) was isolated by separating the extracellular proteins of A. clavatus VKPM F-1593 via isoelectric focusing. The studied keratinase was an alkaline subtilisin-like non-glycosylated protease active over a wide pH range with optimum keratinolysis at pH 8 and 50 °C.

Fibrillar proteins play a significant role in the functioning of living organisms, and much attention has been paid to them recently as targets in the ther

Keratin-containing wastes (feathers and bristles) make up the majority of all animal wastes, a fast-growing agricultural sector that annually increases pro

Проведен поиск среди наиболее известных полимеров (альгинат, каррагинан и акриламид) для использования в качестве носителей клеток мицелия Aspergillus ochraceus ВКМ-F4104D – продуцента фибринолитической протеазы-активатора протеина С плазмы крови человека при его г-лубинном культивировании. Показны морфо-цитологические особенности развития мицелия A. ochraceus ВКМ-F4104D в гранулах каррагинана и альгината кальция. Оптимизированы условия культивирования микромицета, иммобилизованного в гранулах 3.5%-ного альгината кальция. Показано, что иммобилизованные клетки мицелия продуцента имели повышенную стабильность и были способны синтезировать протеазу-активатор протеина С плазмы крови на максимальном уровне в течение 10 сут и более. Кроме того, иммобилизованные клетки мицелия при культивировании могли быть использованы многократно (до 5 циклов).